Cub Cadet 3225 (MTD) stalling

[jrseaman]

I have a Cub 3225 with a Kohler Command 22 engine. 410 hours, always well cared for.

Problem: Starts right up. After 3 - 4 minutes starts missing, then will die completely with the usual backfiring (which the neighbor's kids get the biggest kick out of.) Will start right up again, run for a few seconds and start missing/backfiring again. If I keep re-starting it, after 5 or 6 attempts it will run and stumble, and run and stumble, but eventually after it gets hot - and after it sounds like I have shot the entire neighborhood - will keep running fine.

So far I have: replaced both coils, voltage regulator, fuel filter, fuel pump, plugs, air filter, fuel solenoid in the carb, ignition switch (melted hot wire) and fuel line from the tank to the filter. Have also cleaned the carb and fuel cap vent.

None of this has had any affect.

I'm stuck. ANY help will be appreciated.

 

[kredlinger]

hmmmm, almost sounds like a possible sheared flywheel key?

 

[jrseaman]

Others I've talked to yesterday have narrowed it down to a 'SAM' which is some type of variable timing module MTD put on older motors (mine's a '99) to make starting easier. (My description of what they do may not be 100%, but when they go bad things don't run right.) Apparently they do go bad and I've replaced everything else. So...once more out comes the engine.

I will check the flywheel when it's out.

Thanks for the input.

 

[kredlinger]

Spark Advance Module, yup those can go belly up. A good repair shop will have a tester that simply connects to the box & can test each side of the box (brown & yellow wire) for analog, pink & brown for digital

 

[jrseaman]

Thanks. I'll call around to see if any of the local shops can test those things.